1. What is BMI-for-Age?

BMI-for-age is a measure that compares a child's body mass index (BMI) to other children of the same age and sex. It's the most common screening tool for identifying weight problems in children aged 2-20 years.

2. How Does the Calculator Work?

The calculator uses the standard BMI formula:

Where:

• \( weight \) — Body weight in kilograms
• \( height \) — Height in meters

Explanation: The result is compared to CDC growth charts to determine the percentile for the child's age and sex.

3. Importance of BMI Calculation in Pediatrics

Details: Pediatric BMI assessment helps identify potential weight problems early, when lifestyle changes are most effective. It's more appropriate than adult BMI categories for growing children.

4. Using the Calculator

Tips: Enter weight in kg, height in meters, and exact age in years. For most accurate results, measure height and weight in light clothing without shoes.

5. Frequently Asked Questions (FAQ)

Q1: Why use BMI-for-age instead of regular BMI?
A: Children's body composition changes as they grow, so BMI must be interpreted relative to other children of the same age and sex.

Q2: What are the BMI percentile categories?
A: Underweight (<5th %ile), Healthy weight (5th-85th %ile), Overweight (85th-95th %ile), Obese (≥95th %ile).

Q3: When should BMI be measured?
A: The AAP recommends annual BMI screening for all children aged 2+ years.

Q4: Are there limitations to BMI?
A: BMI doesn't distinguish between fat and muscle mass. Athletic children may have high BMI without excess fat.

Q5: What if my child's BMI is high?
A: Consult your pediatrician for evaluation. They may assess diet, activity levels, and family history.